Polysulfide-based resins are used widely in the protection and sealing of components and hardware in many industries that include aviation. In fact, polysulfide-based resins are the primary products of choice for sealing fuel tank compartments. Within aviation, fuel tank sealants are highly regulated by the federal government to provide specific performance qualities. These formulations have been held constant over many decades and are used in many aircraft from small recreational to commercial airlines. The application and maintenance of these materials are also deemed to be regulated and expected to be held constant over many years.
When it becomes necessary to perform repair and maintenance on the polysulfide resin, it is most common to start with complete removal of the material from the area in question. Removal of the resin typically includes scraping and mechanical abrasion, resulting in significant damage to the underlying substrate. When substrate damage occurs, as is commonly the case, the surfaces must be reconditioned, requiring the use of several steps and significantly increasing the resources and cost of the original task. Attempts to use solvents render it impossible to control the cleaner to select areas or to vertical and overhead structures. When this fails, the operator typically defaults to the option of using mechanical action. Therefore, current practice in the maintenance and repair of polysulfide resin is labor-intensive and costly.
As a consequence of the needs for an effective and practical dissolution mechanism for polysulfide resin, the gel of the present invention was developed and found to be effective. The gel adheres well and allows the chemical formulation to be in direct contact with the cured polysulfide resin present on vertical and overhead surfaces. Reacted polysulfide may be easily wiped away to complete the task or when thick layers of material must be removed, additional gel-form of the chemistry may be added to repeat the process. Where necessary, a rinse may be used instead of wiping with a rag or napkin. Rinses include alcohol or water which causes the reacted polysulfide and gel to emulsify and disperse, allowing small orifices and cracks to be rinsed and left clean.